A total of 170 ceramic specimens from 16 archaeological sites representing 16 well determined ages from 4000 BC to 150 AD were investigated using the Thellier method. These paleointensities were compared with data from countries near Egypt after reduction to a common latitude to determine a secular variation curve of the geomagnetic field for the time period from 4000 BC to 150 AD. The field intensity increases from about 30 pT around 3500 BC to a maximum of 70 µT at about 400 BC when it starts to decrease until 150 AD. The Thellier double heating method was used together with the following additional test measurements: a) during the Thellier experiments the laboratory field FLsb. pointed in the direction of stable NRM, b) magnetic susceptibility was measured after each double heating step to check for chemical alteration, c) a TRM check was made, by repeating the pTRM induction at a lower temperature, d) recent samples which were fired in a known field were used to test the reliability of our experimental setup and method. Based on rock magnetic measurements magnetite was identified as the predominant carrier of magnetization in the ceramics and bricks.

Rock magnetic properties of the Nile mud are reported. They indicate that the carrier of magnetization in the Nile mud is predominantly magnetite. Fourty air-dried ceramic samples made of Nile mud were manufactured to ceramics by stepwise heating to 700• C at various field intensities between 0.03 mT and 0.09 mT and with various angles θ between the laboratory field (F L ) direction and the ceramics. The partial (pTRM) and the total thermoremanent magnetization (TRM) increase linearly as the magnetic field (F L ) increases. The rate of increase of the pTRM with both F L and temperature T depends on θ , so that it decreases by 25% as θ increases from 0• to 90• . In extreme cases, the effect of the magnetic anisotropy results in overestimating the determined palaeointensity by 33% and underestimating it by 25% from the correct value. The direction of TRM is the same as that of the ambient magnetic field independent of the anisotropy. Applying the laboratory field in the direction of the stable natural remanent magnetization during a Thellier-type experiment results in accurate determination of the palaeointensity.

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Geoelectrical resistivity and resistance geoscanning techniques were conducted on Behbiet ElHigara and ElKom ElAkhder archeological sites for two purposes. The first was aimed to study the palaeohydrography and the subsurface geological picture of these sites; for this purpose, 19 vertical electric soundings were conducted along two E-W profiles across the sites. The results indicate that both archaeological sites represent buried high sand gizeras occupied by the ancient Egyptians as they were safe from the high floods and near to the freshwater courses that passed by the sites. The second purpose was to delineate any buried archaeological remains under the soil. For this purpose, resistance geoscanning survey was conducted on the two sites, together with three detailed and shallow geoelectric resistivity profiles along ElKom ElAkhder for more confirmation. The results indicate that the low-resistivity clayey deposits predominate on the two sites. Behbiet ElHigara is characterized by shallow, circular and small-extent anomalies that could be referred to small granitic blocks at shallow depths, whereas at ElKom ElAkhder, a high resistivity anomaly embedded within a low resistivity clayey facies was noticed: this could represent the buried sand gezira (islet) of ElKom ElAkhder.

The ancient Egyptian Abedju (original name of the present Abydos) locality is a famous archaeological site southwest of Balyana town, Sohag Governorate, Upper Egypt. It is located to the west of the agricultural land of the Nile Valley. The locality represents one of the most important burial grounds for kings and high court dignitaries in ancient Egypt. Shallow geophysical techniques are considered as one of the most accurate and cost‐effective methods used in archaeological prospecting and are considered as rapid and safe techniques in detecting a wide range of buried archaeological features. The geoelectric resistance scanning technique, using the Geoscan RM‐15 Resistance Meter, is applied with a twin‐electrode configuration at three sites of the unexcavated localities of Abydos area. This technique proved to be a useful means of exploring the sites through mapping the subsurface burial inhomogeneities resulting from the marked resistance contrast between the buried stone and brick walls and the covering fill of sand, silt and clay. Interesting different buried features are imaged and displayed on maps and three‐dimensional representations to guide the archaeological excavation programmes at the sites of Umm El‐Qaab, Shunet El‐Zebib and Kom El‐Sultan within the Abydos region. At the Umm El‐Qaab site the combined interpretation of the tomography resistance ranges and maps indicate buried walls and rubble as well as an amorphous background area. At the Shunet El‐Zebib site, the texture of the images, which show scattered and crowded high‐resistance anomalies, confirms the existence of buried tombs at the site, which is surrounded by defence walls. Thus, this site was not a fortress or a palace, but a special cemetery for higher dignitaries. Kom El‐Sultan, however, shows a concentration of high‐resistance anomalies at the northern part. Thus, these may be related to walls and rubble related to a nearby elevated temple. Copyright © 1999 John Wiley & Sons, Ltd.